AUTO DOOR LOCKS

For a little while now, the auto lock function in my car has worked on and off. Sometimes when I put my car in gear the locks would engage the way they are supposed to, other times they wouldn't. A few days ago they stopped working altogether and haven't started working since. None of the power lock buttons in the car activate the locks, my interior/dome light doesn't come on when a door is opened (but the lights do work if I turn them on manually) and my sunroof control switch doesn't work either. I've checked the fuses and they were ok, but I don't know if this could be a door lock relay problem or if there is something else wrong? Any ideas/advice would be greatly appreciated.